In apartment complexes and the like, electrical energy can be conserved by converting from existing master-metered systems to individual tenant metering. Specifically, we are concerned with those apartment complexes in the Sun Belt, in which raintight panelboard enclosures, mounted on the exterior walls of the buildings, are equipped with a single main breaker, usually of 200-ampere rating, bussing of the same rating, and enough bus-mounted "stabs" to provide an adequate number of branch-circuit breakers for two or more apartments. The individual panelboard may be one of several served by an underground feeder from a pad-mounted transformer located nearby. The primary of such a transformer may in turn be served by an underground 7200-volt feeder, looping from transformer to transformer, but fed at one point from the utility supply, at which point the master meter is usually located.
Present methods of coversion from master-metered installations to individual tenant metering, many examples of which may be seen in the Houston area, generally employ the following method: The existing panelboard-enclosure may be removed from the wall (if surface-mounted), or the brick around it is broken out (if recessed), and the end of the underground feeder conduit is cut off, and terminated in a large raintight junction box, set within two or three feet from the ground; the feeder conductors now terminate in this box; above this box are mounted a bank of meter-sockets, and above the sockets are mounted new individual raintight panelboards, one for each apartment and one for the building service if necessary; raceways are next extended from the old gutted panelboard enclosure to the new individual panelboard enclosures, and the branch circuits are extended and and spliced as necessary; new circuit-breakers are installed, and the old breakers, if of a different manufacturer, are discarded, along with the old interiors and other hardware.
The existing panelboard enclosure, serving two or more apartments, may have been neatly mounted on the wall surface or recessed within the brick veneer in a space of approximately fourteen inches wide by thirty inches high.
The revised installation requires extensive brick removal, shortened service conduits, rerouted service conductors, additional junction boxes or gutters, new individual tenant panelboards, and a plethora of conduits or raceways run from the new panelboards to the old gutted panel, now reduced to a splice box. To compound the problem, there may not be enough space for this massive amount of new equipment, since the existing panel may have been mounted between windows, or at the corner of a building, where a wall space of approximately one foot is all that may be available for the conversion equipment. Frequently, a large plywood panel may be used primarily for mounting the new boxes, and it may be used secondarily to cover the large hole of several square feet due to the removal of the brick. The prior integrity of the brick veneer wall against rain and moisture has now been replaced by a caulked joint at the edge of a plywood panel and the remaining brick surface, hardly an equivalent substitute.
This crude meter conversion system, therefore, is unsightly, takes up a great deal of wall surface, may have to be remotely located from the existing panelboard for lack of room, and is expensive. Yet it represents the state of the art in mid 1978, and many hundreds of meter loops are being converted by such crude methods, using standard stock materials and equipment available to local electrical contractors from their wholesalers.
Furthermore, construction of many apartment complexes was of the most competitive type and brick ties, if provided, are inadequate to hold the higher courses of brick in place after removal of those required for recessing the box.
A novel box, is therefore a part of this invention, combining conventional raintight construction with a brick-sized blister or extension on the back of the box. This permits removal of one brick, or equivalent in one course, and provides access to the side of the recessed panel box; and the supporting brick-shaped extension, if made of suitable gauge of metal in the manner disclosed, is more than equivalent to that of the removed brick.
In another embodiment, a novel elbow-like transition, essentially fabricated of standard electrical conduit, may be bolted or welded to the back of the junction box. Conventional elbows, even of the short-radius or street-ell type are too bulky for use in the cramped space for these metering applications. The novel ship-ventilator-like section of this novel elbow-like fitting facilitates the mechanical redirection of the heavy feeder (now service) conductors into the junction box, a problem of considerable difficulty for the large wire sizes (say 4/0 to 250MCM copper or aluminum) frequently used to feed those panels, yet requires only the removal of one brick or its equivalent.
In another embodiment, a modification of the novel elbow-like fitting is connected directly to the meter column, dispensing with the junction box entirely, and the line and load wires to the individual meter sockets are aligned and brought through an elbow-like fitting and are connected to the heavy feeder (service) conductors within the existing panelboard, if recessed; if surface mounted, a simple nipple connection between meter column and panel enclosure is employed.
This is made possible by a novel connector for the heavy feeder conductors to the individual meter line-conductors. This connector takes little more space than the conductor itself, and has an insulating sleeve. With such an improvement, the space required for the connections can be obtained within the existing panels and the problem of rerouting the heavy feeder wires into the junction-box nipples or junction-box extension avoided.
The unique metercolumn, which may be mounted horizontally, has great appeal to utilities.
Utilities, the Houston Lighting and Power Company included are reluctant to stock and install more than one style of meter socket and enclosure, because they must also stock the necessary replacement parts. Thus, for example, the Houston Lighting and Power Company stocks the standard 100-ampere General Electric meter socket, Cat. No. 582X23, or its Westinghouse equivalent, and the terminal clips and hardware, but is understandably reluctant to purchase more than one of the Plethora of ganged meter sockets presently manufactured to meet the individual metering requirements for apartment complexes or the like. The novelty of this invention for gangable sockets has been disclosed in patent application Ser. No. 889,109, but this application discloses improved means of connecting line and load leads to the terminals of the General Electric and Westinghouse meter sockets, or their equivalents.
In the interests of compactness, because the column may have to be mounted in a restricted space on a finished exterior wall, it is desired to have the meter-supporting column as small as possible, completely sealed against the entry of rain or moisture, and tamperproof. A tube of regular cross-section, say two by four inches, is well suited for this purpose, and the General Electric circular meter sockets mount well thereon.
To assure sealed construction, and because the cross-section of the column is so small, the preferred embodiment of the invention employs insulated wires for both line and load leads to each meter socket.
A novel part of this combination is the replacement panelboard interior, with the subdivided bussing for individual apartments mounted on one pan, integral alignment devices for mounting within the existing enclosure, and for safety, a dead-front panel dimensionally variable to fit the width of the existing enclosure. Novel panelboard interiors of this design may be made for the panelboard enclosures manufactured by Federal Pacific Electric Company, ITE, General Electric Company, Square D Company and others, by simple variations in bussing insulation and spacing.
Accordingly, it is a primary object of the present invention to provide a further improved apparatus to facilitate the conversion from master-meter to tenant metering as outlined in the foregoing paragraph.
A further object of this invention is to disclose an improved method of making feeder-(now service)-to-meter connections within the cramped space within the existing panelboard, rather than within the junction-box at the base of the meter column, to avoid excessive manipulation of the heavy feeder (now service) conductors and to provide more compact junction boxes, to effectively reduce the overall height of the meter column, because most utilities prefer that meter faces be centered between four and six feet above grade.
Other objects, advantages, and features of the present invention will become readily apparent to those skilled in the art upon consideration of the following detailed description and with reference to the following drawings, wherein like elements have been identified with like numerals, in which: